Wrong java -version being reported

I am running Windows 7 Professional x64 and have the following Java versions installed:

x64

• C:\Program Files\Java
  • jdk1.6.0_24
  • jdk1.7.0_04
  • jdk1.7.0_07
  • jre6
  • jre7

x86

• C:\Program Files (x86)\Java
  • jre1.6.0_07
  • jre6
  • jre7

in my environment variables I have my PATH containing C:\Program Files\Java\jdk1.6.0_24\bin and JAVA_HOME set to C:\Program Files\Java\jdk1.6.0_24\bin

However running java -version reports

java version "1.7.0_07"
Java(TM) SE Runtime Environment (build 1.7.0_07-b10)
Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode)

How is this the case when there is no reference to this version of Java in my Environment variables.

Any help on this issue would be great as I am trying to run Apache ANT using Java 1.6.

You're probably have java.exe copied over to one of system paths (AFAIK that's Java installer default behavior). To check what actually executes when you run 'java -version' run from command line:
for %I in (java.exe) do @echo %~$PATH:I and it will tell you where it is.

When installing a public JRE (used by the Java plugin), a java.exe file is also created in C:\WINNT\system32 (IIRC). It's probably this java command that is executed, since C:\WINNT\system32 comes before the JDK/bin directory in your PATH.

Put the JDK/bin directory at the beginning of the PATH

The PATH folders are checked in the order they appear. Try moving the java path to the front. If that fixes the issue then you have another version somewhere on your path.